Blood lead levels and bone turnover with weight reduction in women

Abstract

High bone turnover states are known to raise blood lead levels (BPb). Caloric restriction will increase bone turnover, yet it remains unknown if weight reduction increases BPb due to mobilization of skeletal stores. We measured whole blood Pb levels ( 206 Pb) by inductively coupled plasma mass spectrometry in 73 women (age 24-75 years; BMI 23-61 kg/m 2 ) before and after 6 months of severe weight loss (S-WL), moderate weight loss (M-WL), or weight maintenance (WM). Baseline BPb levels were relatively low at 0.2-6.0 mg/dl, and directly associated with age (r ¼ 0.49, Po0.0001). After severe WL (À37.4 ± 9.3 kg, n ¼ 17), BPb increased by 2.1 ± 3.9 mg/dl (Po0.05), resulting in BPb levels of 1.3-12.5 mg/dl. M-WL (À5.6 ± 2.7 kg, n ¼ 39) and WM (0.3±1.3 kg, n ¼ 17) did not result in an increase in BPb levels (0.5±3.2 and 0.0±0.7 mg/dl, M-WL and WM, respectively). BPb levels increased more with greater WL (r ¼ 0.24, Po0.05). Bone turnover markers increased only with severe WL and were directly correlated with WL. At baseline, higher calcium intake was associated with lower BPb (r ¼ À0.273, Po0.02), however, this association was no longer present after 6 months. Severe weight reduction in obese women increases skeletal bone mobilization and BPb, but values remain well below levels defined as Pb overexposure.

Detectable Blood Lead Level and Body Size in Early Childhood

“…While previous studies have suggested reverse causality, that is, weight loss leading to release of lead from body stores and subsequently higher BLL [5, 36], it is less likely that weight loss would explain the results we found in the current study, for several reasons. First, the measurement of BLL preceded body size measurement.…”

Urinary heavy metals and associated medical conditions in the US adult population

“…They found an inverse correlation of cadmium, cobalt, cesium, and lead with obesity. It has previously been reported that severe weight loss could increase bone turnover (Hyldstrup et al 1993;Svendsen et al 1993;Ricci et al 2001) and could partially explain a rise in lead blood level (Riedt et al 2009). Inconsistent with our findings, other investigators suggest that lead could induce lipid peroxidation, alter insulin response, and consequently promote diabetes associated with obesity (Evans et al 2002;Wellen and Hotamisligil 2005;Shoelson et al 2006).…”

Obesity and bone metabolism

“…It is also associated with an increase in markers of bone formation (serum osteocalcin) and bone resorption (serum N-telopeptide of type I collagen, pyridinoline, deoxypyridinoline) [73]. Another interesting finding is that a history of chronic dieting behavior is associated with detrimental effects on bone health, even in obese women [74].…”